Rocket wall construction



Dec. 25, 1962 M. L. vEsr, JR 3,069,847

ROCKET WALL CONSTRUCTION Filed Dec. 1o, 1959 f mi@ /NVENTCR MARv//v 1.. vssr JR.

A T TORNEV 3,069,847 ROCKET WALL CONSTRUCTION Marvin Lewis Vest, Jr., Glastonbury, Conn., assigner t United Aircraft Corporation, East Hmtford, Conn., a corporation of Delaware Filed Dee. 10, 1959, Ser. No. 858,718 3 Claims. (Cl. Gil-35.6)

The present invention relates to a rocket wall construction for use as the combustion chamber wall or as the wall for the nozzle.

One feature of the invention is a normally imperforate wall construction but which in the event of local overheating of the wall will become porous to allow a ilow of coolant therethrough.

Another feature of the invention is a porous wall of high temperature material having the interstices filled with a material that will melt before the critical temperature of the high temperature material of the wall is reached. An other feature is the use of this porous wall as the inner element of a double element wall lwith a cooling space between the elements so that as the lower melting material is melted out of the wall the coolant between the `wall elements will discharge through the porous wall for cooling the hot area.

Other features and advantages will be apparent from the specification and claims, and from the accompanying drawing which illustrates an embodiment of the invention.

FIG. 1 is a longitudinal sectional View through the rocket.

IFlG. 2 is a sectional view on a larger scale of a portion of the rocket wall.

FIG. 3 is a view similar to FIG. 2 showing the effect of a hotspot on the chamber wall.

Referring first to FIG. l, the rocket has a substantially cylindrical wall 2 deiining the side walls of the rocket, a head 4 at one end of the cylindrical wall 2 and a nozzle 6 at the other end. The nozzle has the usual convergent divergent configuration and in the arrangement shown, the nozzle wall is a continuation of the chamber wall. The wall 2 is made up of an outer shell 8 of high strength high temperature material and an inner wall 10' also of high strength material. The inner wall is held in concentric relation to the outer wall and spaced therefrom by radially extending spacer elements 12. As shown in FIG. l, coolant is admitted through a duct 14 into the space 15 between the inner and outer shells and this coolant which forms one of the propellants is discharged into the combustion chamber through nozzles 18 in the inner element 2t) of the end wall 4 of the rocket.

The other propellant which may be the fuel is delivered to a manifold 22 and thence through tubes 24 extending through both the inner element 261 and the outer element 26 of the end wall 4. The inner ends of the tubes 24 constitute nozzles for the propellant.

The inner shell lll is made of a high temperature material that is sutiiciently porous so that passages are formed through the wall to permit coolant from the space 16 between the inner and outer shells to ow through the shell 10 and discharge into the combustion chamber. One example of a material that would be suitable for the shell lil is a plurality of stacked layers of woven stainless steel cloth welded together to provide desired strength and porous properties. This shell 1) is normally made impervious to the cooling fluid by lling the porosities or arent O critical temperature of the stainless steel mesh.

3,069,847 Patented Dec. 25, 1962 ice interstices of the material with another material Z8 that has a melting point somewhat lower than the critical temperature of the material forming the shell 10'. 'For example, the interstices of the stainless steel cloth layers could be filled with aluminum which has a high thermal conductivity and which melts at a temperature below the It will be understood that the porous shell 10V may be made of other suitable materials and impregnated with another diiferent material having a substantially lower melting temperature.

Under normal operation of the rocket, the tiller material for the porous wall 10 will remain in place and coolF ing of the wall 10 may be accomplished by the rapid conduction of heat through the shell 10` to the coolant iiowing through the space 16. However, if a hot spot occurs within the combustion chamber or nozzle and begins to overheat an area of the inner shell 10, the iiller `material in this shell will he melted out in the overheated area so that this material will be blown out of the interstices or porosities by the pressure of the coolant such that coolant will then ow through the porous wall to cool the wall and to provide a cooling iilm over the surface ofthe wall 1t).

ln order that the filler material may be blown out by the coolant, the latter must be under a pressure higher than the pressure within the combustion chamber or the nozzle itself. Since it is common practice to use as a coolant one of the propellants in a liquid fuel rocket, the pressure within the space 16 will be at a pressure above that within the combustion chamber by the arrangement shown, since in order for the coolant to tlow through the injection nozzles 1S, the pressure upstream of the injection nozzles must be higher than that downstream of the nozzles or within the combustion chamber. One coolant that might be used for this purpose could be liquid hydrogen or liquid oxygen in which case the propellant in the manifold 22 would be the other of these two substances.

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described, but may be used in other ways without departure from its spirit as defined by the following claims.

I claim:

1. A rocket wall construction including an outer impervious shell, an inner shell spaced from said outer shell to provide a coolant space therebetween, said inner shell being in direct contact with combustion gas-es in the rocket, said inner shell being porous and the pores thereof being lled at least in part with a low melting heat conductive metallic material thereby normally to prevent escape of the coolant through the porous shell, said pores in said inner shell providing passages from the coolant space to the inner surface of the inner shell when the inner shell becomes excessively hot and the low melting material is melted out of the pores, and a coolant in said coolant space at a pressure higher than the operating pressures within the rocket.

2. A rocket wall construction including spaced outer and inner walls defining therebetween a coolant space, the inner wall being in direct contact with combustion gases within the rocket and having a plurality of passages therethrough, a low melting heat conductive metallic material till-ing said passages, at least in part, the low melting material having a lower melting point than the critical temperature of the material of the inner wall, and a fluid References Cited in the le of this patent UNITED STATES PATENTS Skoglund July 18, 1944 Nicholson Nov. 10, 1953 Goddard Feb. 2, 1954 Hoadley Oct. 13, 1959 Fox et al. Jan. 26, 1960 

